image: GreenCarCongressEmissions That Slow Warming Subtracted From Those That IncreaseRather than looking at the sources of different chemicals linked with global warming, the GISS study looked at net climate impact from different economic sectors. By net impact, we're talking about emissions than contribute to warming (the usual suspects CO2, methane, black carbon, etc) minus those emissions that actually slow warming (some aerosols, sulfates, etc) by reflecting light and altering clouds.

The industrial sector releases such a high proportion of sulfates and other cooling aerosols that it actually contributes a significant amount of cooling to the system. And biomass burning--which occurs mainly as a result of tropical forest fires, deforestation, savannah and shrub fires--emits large amounts of organic carbon particles that block solar radiation.

it should be noted that in that 'motor vehicles' description, that does not include aviation, which as an industry was ranked well down on the list of net climate contributors--but above the shipping and industrial activities.

So how where does that leave us as far as making technological and societal changes?

photo: ITDP-EuropeGreen Cars Are Good, But No Cars is Better Creating cars and trucks running on clean electricity is no doubt part of the solution. But we're well on our way to doing that, at least conceptually and in the public imagination. We know we need green cars. However that is really only a small part of the solution and frankly seems sometimes like a distraction from the bigger issue, which is all too often sidelined. What we don't seem to know yet is that we need to create communities and spaces where for the vast majority of people an owning an automobile is not required in their day-to-day lives.

As Zarchary Shahan correctly states over at CleanTechnica the benefits of this are numerous:

Getting out of the automobile habit altogether would be a great step forward for our society and the world. It would address this #1 climate change (and ocean acidification) concern, but it would also help address obesity tremendously, the economy, and other things. As Alex Steffen of Worldchanging writes, "we already know that the way to solve the problem of cars is to build better cities."

It's also in building better towns and expanding multi-modal public transit options, but "build better cities" is a decent simplification.

photo: Jason AnfinsenChanging Your Diet = The Greatest & Greenest Personal Lifestyle ChoiceAs far as your diet is concerned, it really isn't as complicated as creating a new urban infrastructure. And strictly from an environmental perspective comes down to this: Eat Less Meat.

Personally I recommend eating no meat at all--the health, mental, and spiritual benefits are myriad and profound--but when it comes to addressing the environmental problems of our growing meat consumption, simply consuming meat at much reduced levels is sufficient, particularly reduction of meat from ruminant animals such as cows and sheep.

TreeHugger's Graham Hill recently pitched the concept of being a weekday vegetarian at the TED conference, and that's a good goal. If the majority of people simply returned to that level of meat and dairy consumption we'd be well on the way towards a more sensible and sustainable scale of animal husbandry.

A new study coming out of NASA's Goddard Institute for Space Studies, and published in the Proceedings of the National Academy of Sciences, shows that when it comes to the net contribution to climate change on-road